Unidirectional-flow steam-engine.



J. DAVIDSON & W. 0. LARMUTH. UNIDIRECTIONAL FLOW STEAM ENGINE. APPLICATION FILED 00T.5, 1912.

2 SHEETS-SHEE'L l.

Patented 001;. 6, 1914.

J. DAVIDSON & W. 0. LARMUTH. UNIDIREGTIONAL PLOW STEAM ENGINE.

APPLICATION FILED 00T.5,1912.

2 SHEETS-SHEET 2.

Patented Oct. 6, 1914.

Wwses- A UNTTED 1 sTATEs PATENT oEEioE;

JOHN DAVIDSON, F PENDLETON, AND WILLIAM OLIVEBLABMUTH, OF SALFORD,

ENGLAND.

UNIDIBEGTIONAL-FLOW STEAM-ENGINE.

Specification o1' Letters Patent. Application lled October 5, 1912. Serial N o. 724,129.

PatentedOet. 6, 1914.r

county of Lancaster, England, have inventval? .ed certain new and useful Improvements in and Connected with. Unidirectional-F low Steam-Engines; and we do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it rtains to make and use the same.

ur invention relates to improvementsl in and connected with uni-directional flow steam engines in which means are rovided for taking steam from the engine or heating and other auxiliary purposes after it has expanded in the usual way to some predetermined ressure. Hitherto such means consisted o valves opened `automatically by the steam and allowing. the escapeof a fixed quantity of vsteam from the cylinder after a certain amount of expansion has taken place. n

The ob'ect of our invention is to provide means, w ereby the amount of 'steam taken Vfrom the cylinder ca'n be varied automatically to suit requirements,and whereby the engine may be run as an ordinary condensing engine under most economical conditions, when steam Afor heating purposes and thelike is not required. We attain these objects by the mechanism illustrated in the accompanying two sheets of drawing, in which: U

Figure 1 is a part sectional front View and Fig. 2 a side view showing an embodiment of our invention. Fig. 3 isa detached plan. Fig. 4 is a sectional front view and Fig. 5 a part sectional side view of a second embodiinent of our invention.

Similar letters refer to similar parts throughout the several views.

Referring to the figures generally, we provide opposite the steam admission valves a., a two piston valves b, b, which act as auxiliary valves and are secured to a rodv c, which is connected up to 4an eccentric c on the crank shaft of the engine (not shown). The piston valves b, b are provided with inclined slots vrl y which normally correspond with similar slots e in the valve linings f. Two ports g lead from the slots in valve linings f to the cylinder h of the engine. The steam leaves the slots in the valve linings f by the pipe c' which leads into tlie exhaust pipe or to any desired place.

The valves b, b may be turned `by the followin mechanism :-`-The valve rod c is slidab y connected to one end of an arm which is pivotally connected at its' other i end to a piston rod l, the piston m of which works in a relay cylinder n and is actuated by oil, steam, water or the like under ressure. This motive fluid is controlled. y a. 1slide valve o connected by a linkp to a straight lever g pivoted on a lever r. The

lever is connected to one arm f a bell.

i cranlolever a b a link t. The lever fr is pivoted at one en to a fixed bracket and at the other to an arm u linked to the piston rod Z and fulcrumed on the engine body. The second arm of the lever s 1s connected to apiston rod c the piston w of which is under the influence 'of a spring m. The cylinder i/y of the piston w is conliected by a pipe e to the auxiliary main. The partsv are so arranged that when the engine is working un-4 der ordinary conditions, the piston w will be in the center of its travel.

`The operation of the means described is as followszSteam admitted in the usual way is expanded until a predetermined point is reached at which the"auxiliary 4Valves I), b will be opened by the eccentric c and allow the steam to escape until another predetermined point is reached, when the aux.- iliary valves b, b, will be closed; expansion will be. then continued in the cylinder hand the remainder of the steam exhausted in the usual way.

The period I of opening the auxiliary valves b, b as previously stated will be regulated to suit circumstances and varied auto-- matically by the pressure in the auxiliary steam main, acting upon the described mechanism. For example, if the pressure falls` in the said auxiliary main, the piston fw will be moved by the spring m and) t'lie motivel fluid thereby admitted to one side of the piston lw and move the sz'i'me, this movement being transmitted to the valve rod c, which is turned, and causes the slots (Zand c to be correspondingly'displaced in relation to each other. The'valves b, b will then allow more steam to enter the mains. If the pressure in the auxiliary main increases, the piston fw 'will be moved in the opposite direction, and the valves b, b so moved thereby as to allow less steam to enter the said mains.

When steam is not required for heating or other-auxiliary purposes, the piston valves b will not open at all and the engine will run as an ordinary engine. According to the amount of steam required, the engine governor will regulate' the amount admitted to the engine in the well known manner, so thatl it will be capable of doing the work required although a large quantity of steam is taken out of the eylmder for auxiliary or other purposes.

The means described perghit of running the engine always under ecl nomical Aconditions and yet automatically andv economi- 'cally supplying steam when required after it has done Work in the engine for auxiliary purposes,

lVe may also attain the object of our invention by using ordinary piston valves in lieu of the hereinbefore described angular ported valves, and regulating the time of opening by means of a variable eccentric.'

controlled by similar means as those described for turning the said angular ported valves. Figs. 4 and 5 show an arrangement of this kind, in which 2 are the piston valves actuated by the variable eccentric 3, which may be of any suitable construction. For example the same may consist of-an eccentric disk l having a slot 5 in which is situated av block 6 on the crank shaft 7 of the exigirle.. The block G is provided with transverse keys S which slide in slots in the eccentric disk 4 which is prevented Yfrom sliding hy its strap and rod connected to the guided rod r, and two arms 9 riffidly connected to a sleeve 10 on ythe shaftl 7. The sleeve is moved longitudinally by means of a ring ll rotatable on the same and a lever 12 connected to th(` ring 11. The extent of the movement of the piston valves@ is regulated by means of the relay cylinder n the piston rod Z'of which is connected to the lever I2. and actuates the same, thereby moving the block 6 and its transverse keys H the latter causing the eccentric disk to he moved at right angles to the crank shaft 7 and change its degree of eccentrieity. lhe movement of the relay cylinder piston is obtained and controlled by the same means and in the same manner as described with reference to Figs. 1, 2, and 3.

Wd claim y l. In a uni-directional flow steam engine, an auxiliary exhaust port in each extremity of the Working cylinder, valve casings With openings communicating with the said exhaust ports, an auxiliary exhaust pipe independent from the main exhaust pipe in open communication with the said valve casings for supplying steam f r auxiliary purposes, and a mechanically and positively actuated valvein each of the said casings with variable movement in relation toA the said openings, for opening and closing the saidy openings to a variable extent during the Working stroke of the piston and l'iefore the central exhaust ports are opened. for the purpose of varying the amount of steam.

casingsfor supplying steam 1For .auxiliaryA purposes, and a valve in each of the said casings operatively connected to the crank shaft of the engine and with'a movement in relation to the openings to the said valve casing. varying in accordance with thepressure momentarily existing in the said auxiliary exhaust pipe, for opening and closing the said openings to a variable extent duringl the working stroke of the piston and before the central exhaust ports are opened. for the purpos(` of varying the amount ot' steam passing duringr the working stroke through the said auxiliary exhaust ports in arcor-(laure with the momentary requirements and irrespective of the momentary pressure existing in the Working cylinder.

ln testimony whereof we have allixed our signatures in presence ot' tivo witnesses.

JOHN DAVIDSON. WlLLlM (.)lilflll LA lllll'l'lll.

W il nesses l". Boruxnn. S'rxxnuv ll. luxuxmh soA il o 

